Flow equalizer



March 14, 1944. J. A LAUK I 2,343,912

. FLOW -EQUALIZER l f 'Filed Jan. 17, 1940 2 Sheets-Sheet 1 March 14, 1944. '1. A. LAUCK 2,343,912

FLOW EQUALIZER Filed Jan. 17, 1940 2 SheetsSheet 2 Patented Mar. 14, 1944 FLOW EQUALIZER John A. Lauck, Cleveland, Ohio, assignor to Pesco Products Co., a corporation of Ohio Application January 17, 1940, Serial No. 314,209

(Cl. 24d-85) 6I Claims.

This invention relates to synchronizing arrangements, and more particularly to arrangements for equalizing the flow of uid to a plurality of remotely located hydraulically operated units under conditions wherein the different units may be subjectedV to varying resistance opposing the operation thereof.A

It is an object of this' invention to provide an improved arrangement for Asynchronizing the movement of a plurality of remotely located fluid pressure operated instrumentalities and more particularly to a metering arrangement for delivering equal quantities of fluid under pressure to two remotely located uid operated instrumentalities irrespective of the varying resistance to movement offered by the respective ones of said .instrumentalitiea A more specic object is the provision of means effective to divide a stream of fluid under pressure into a plurality of separate streams of predetermined fractional quantities delivering the same to two remotely located fluid operated instrumentalities and maintaining this fractional relationship of flow to each instrumentality irrespective of variations in the reslstances to flow occurring in the respective streams.

It is a further object of the present-invention to provide in combination with a. fluid stream divider for delivering fluid pressure to a plurality of remotely located fluid motors subject to varying resistances, said divider having as one of its characteristics a variation in the volumetric capacity thereof with variations in the reslstances4 to flow in the outlet lines therefrom, means which is responsive to a relative rise of pressure in one thereby causing said divider to always operate at its maximum efficiency and said motors to be synchronized irrespective of varying resistances encountered thereby.

Another more specific object is the provision of a synchronizing arrangement for effecting duplication of movement of a pair of remotely located fluid piston motors operating aircraft landing flaps, wing tip floats, vlanding gear and other units that must be operated simultaneously and in close synchronism.

Further and more specific objects, advantages, and uses of my invention will become apparent from a reading of the following detailed specification taken in connection with the drawings forming a part thereof and wherein:

Fig. 1 is a schematic layout of an assembly` Referring in greater detail to Fig. 1 for a general understanding of my invention, I have illustrated the same as applied to the problem of synchronizing or duplicating the movement of.

two remotely located airplane landing flaps I0 and Il. It will be readily appreciated that it is of utmost importance that these landing flaps have identical movement since otherwise the equilibrium of the air craft with which they are associated would be seriously interfered with. As is -well known, landing flaps vIll and Il normallyform a pivotal section located in the rear portion of each wing (in the case of a monoplane) and are separated by the main body of the plane, thus making the use of mechanical linkage for synchronizing the arcuate movement of these flaps impracticable.- As a solution to this problem, heretofore a gear type divider similar to that disclosed in Figures 3 and 4 has been employed to divide a fluid stream under pressure delivering the two component parts thereof to two separate piston type of motors associated with the 'respective landing flaps.

I have observed that synchronism is not obtained by such an arrangement and have discovered the reason to be the fact that the volumetric efficiency of the gear type of divider varies with variations in the resistance tov which the respective flaps are subjected. This variation in resistance may be due to several causesincluding differences in the pressure of the air streams to which the respective flaps are subjected, this condition being referred to in the art as a difference in air loading.

lI have discovered that by providing an arrangement of means for imposing lthe same pressure in each of the outlet conduits from the gear divider that the volumetric efciencyoi each side of the gear divider becomes the same and consequently the same identical volume is transmitted to each piston motor irrespective of the variation in the resistance to movement encountered by the respective pistons. .The novel arrangement of means which I have provided and disclose for accomplishing this result in combination with the gear divider is shown more clearly in Figures 2 and 3 and will'be later described in detail.

While the structure of Figure 2 has particular application in combination with the fluid stream divider of Figure 3, it is to be understood that the same has a broader application to any arrangement wherein it is desired to maintain equal pressures at two corresponding points in separate pressure lines. Likewise it is to be understood that while I have disclosed my invention as applied to the operation of aircraft landing flaps because of its particular importance in this connection, I also contemplatethe use of my'invention in similar relations such vfor example asl bly I6 from pressure pump I1 in-tum in communicanon with nuid supp1y. tank la. witn'the valve assembly I6 in the position indicated in Fig. 1, valve I6a and IBcV being held openby their associated cams, fluid will be delivered from pump I1 through assembly I4 and to the respective motors I2 and I3 in kidentical quantities irrespective of the different rsistances oiered byfiiaps I0 and II. When cam operator ISe is moved to a'second position to close valves ISa and I6c and open valves 1Gb and ISd, thenipunip I1 will deliver fluid to the back side of the pistons and cause uid to reverse its flow through assembly I4 and back through valve assembly I6 to tank I8. One way check valves IBf functions to maintain the necessary back pressure for maintaining the pistons in a particular adjusted position, while similar check valves IBg function relief valves against excess pressure.

Referring now in further detail to the construction of assembly I4, Figures 2 and 3, by virtue of which identical volumes of uid are conducted to the adjacent ends of fluid piston mo-` tors I2 and I3,`equalizer assembly I4includes^a gear type fluid stream divider indicated generally at-2I having a single inlet 22 for receiving a uid stream under pressurevand a plurality of outlets 23 and 24 separated from the inlet by pairs of meshing gears effective, incombination gear divider 2I the same, in order tovcause the two sides thereof tooperate at the same volumetriceinciency. Pressure equalizer 30 preferably comprises a single housing 3I of generally rectangular cross-section Yformed with transverse bores 32""andv 33 terminating at their lower ends in threaded inlet openings 34 and 35 threadably receiving in their other ends closure plugs 36 and 31 having depending tubular skirts 33 and 33 adapted to function as cylinders for the reception of the piston portions of a pair of valves in a manner that will appear hereinafter. Interposed between the inlet openings and the tubular skirtsr38 and 39 are a pair of valveseats 4I and 42. A pair ofoutlet passages 43 and 44 communicate with bores 32 and 33 between the ends of skirt members 38, 33 and valve seats 4I and 42.

A special arrangement of valves and operating Vmeans therefor indicated generally at 46 and 41 vare provided for controllingy the ilow past seats proper 43 arranged to be received on seat 42 and `having a tubular. stem portion 43 extending from the rear face thereof and terminating in a pistonlike portion 5| received with a very small clearance within cylindrical skirt 33. Valve stem 49 beyond piston 5I is reduced in size at 52 and receivesV a flexible seal having an upturned outer peripheral portion 53'which as will appear, permits the flow of fluid thereby in one direction, but prevents ow in the opposite direction. Valve stem 49 is formed with a plurality of orifices through the wall thereof in communication with Voutlet opening 44 on one side and with the inside of a return valve 56 operating with the cen'tral orlticed lowerportion of valve 43 providing for return flow; VValve 53. is urged into position where disc valve 48 seats Aon valve seat 42- by A of their respective associated piston members by means of a plurality of radial ports 36 :through the wall of skirt 33 communicating with an annular recess 31 thereabout and through passage 68 corresponding annular recess 63 and ports 13 in skirt 33.

It will-thus appear that should the pressure of the fluid passing valve 43 increase over the pres- Y sure of the fluid passing valve 3l due to any cause whatsoever, such for example as the flaps II being in an air stream of greater pressure than that of flaps I 0, then this will result in fluid passing through the clearance between piston 5I and skirt 33 and past thewall 53 of the seal, through -ports 66, passage 68, and ports 10 in skirt 32 into communication with the seal associated with the l upper stem portion of valve lassembly 46.y Since this seal is constructed in the same manner as the seal associated with the piston 5I of valve assembly 41, .the uid will noty be permitted to pass thereby but will force the wall oi' theseal into sealed relation with skirt-wall 33. This will result in valve 6I being forced downwardly into engagement with seatsV 4I with a pressure exactly equal to the dierence between the presspective sides of the gear divider function with 5 equal volumetric eiliciency and the same identical quantities of fluid will be transmitted to the adjacent sides 'of Vthe piston `motors l2 and 13.

The operation'fof the device under circumstances `wherein the pressure in communication with -outlet 43 rises above pressure in outlet '44 is just `exactly opposite to the.above., namely 'the 'excess pressure will be ltransmitted past the piston and seal of valve assembly 46 through passage 58 and vinto communication with .the piston and seal of valve vassembly 41 holding vvalve 48 against the seat 4Z with a pressure equal to the differential pressure between outlets 33 andV 34.

When a reversal of direction of movement .of motors l2 and. `|3 is desiredcam operator 16e is moved toa position wherein valves IBa and I6c are closed and IBb and 16d are opened and uid is passed .back through equalizer assembly 30,

tons. there is provided a passage 1i in communication with a cylindrical chamber 12 'in turn connected with bore 33 through passage13, its communication being under `the control of a valve are yvaried and hence I havefprovided the above described :novel arrangement of means for maintaining theseoutlet pressures the same.

The construction of the 4gea-r kdivider' shown in VFigure :3 'is not herein claimed as my 'invention other than as `considered in combination with my novel pressure equaliz'ing :assembly shown in Fig- -ure 2 as applied .to the synchronous control of remotely located -motors |3 and devices Il operated thereby.

While I have described my invention in connection with one specific embodiment thereof, it is to be understood that this is by wayV of illustration and not 'by way of limitation, and the scope `of my invention is to be defined by the appended claims 'which .should be construed as broadly as the prior'art will permit.

I claim:

l. In anaircraft control assembly including a pair of arcuately adjustable remotely located aircraft landing 'flaps, duplicate liquid pressureresponsive piston motors for adjusting 'each of said flaps, means for delivering equal quantities assembly including a `disc-'like valve 1G having a l stem 11 extending for a considerable distance within passage-1| and a second stem 18 extending into cylindrical boren. A spring 8| has one end in engagement with. disc valve'lB and the other in engagement with a closure vplug 82, `the end 18 of valve assembly 14 being spaced from the closure plug to provide va limit stop to the movement Vof the valve which prevents portion 11 from being completely 'forced out of passage 1I. The "clearance between stern portion I1 and passage Il provides fora limited-flowwhen valve member 16 is forced away from itslseat, thus allowing the liquid that has accumulated above the valve to leak back into bore 33 whenever; the pressure in said bore .drops below the pressure of the liquidwhich is confined above piston 16. It

will be noted that cylindrical bore 12 .is in com-.

munication with only one of the principal bores, namely, 33.

Closure plug 82' is end of bore 12 vfor the purpose of varying compression of spring 81|. Threaded plugs 84 and 85' serve to close transverse passages in communication with the main bores 32 and 33 f resulting originally from the 'formation of passages 68 and 18 and serving subsequently lto provide access thereto for cleaning.

The gear divider` shown of a well known type. including a pair-of4 meshing gears '9i and 92 `oneach side of,` a -partition 93 in communication on' the inlet side thereof with `common inlet passage 212 and on the outlet side thereof with outlet openings 23 and 24. By virtue of the fact, as shown in Figure 4, that corresponding gears of -each pair are keyed to the same shaft, these gears arel made to rotate together-and hence since they areof the same size, theoretically the .same amount of fluid will be discharged from each of the-outlet openings 23 and 24'. However, as above pointed out, I have found that the volumetric efficiency from the respective sides varies when the outlet pressures 'in Figures 3 and 4 lisv threadablyV adjusted in the of liquid toV each of said piston kmotors for effecting duplication of'adjustment of said flaps irrespective of variations in the air resistance to movement encountered by said respectiveflaps, said mea-ns comprising a housing having a single liquid inlet for receiving a single stream of liquid and a pair of separate outlets for discharging said liquid therefrom in two equally divided streams supplying .said respective ones of said piston motors, saidhousing being formed with a pair of parallel gear unit receiving chambers, each chamber including in lturn apair of overlapping cylindrical bores, gears received in said bores meshingin Vsaid over ng areas,means connetinaaeidsearswe" unison, 'said chambers'bein common'commun ication on the inlet side of `said gears with said single inlet and in independent communication with said separate outlets on the outlet side of said'gears and means in communication with said divided streams vresponsive to an increase in rel sistanceto flow in the divided ystream to one of said piston motors effective to vthrottle the flow in said other divided stream leading to said other piston motor to thus increase the back pressure on Athe corresponding pair of said gears in said otheristreamtothe same value as the back pres- Y vsure on the vother pair `of said gears insaid one of 4said Astreams whereby the volumetric efficiencies of said gear-units are maintained equal and duplicate quantities of liquid are metered to .said vrespectivepis'ton motors for duplicatingthearcuate movement of said flaps. e V

2. In an aircraft controllassembly including a pair of arcuately adjustabl'e'remotely located aircraft landing' flaps, duplicate/liquid pressureresponsive piston motors for adjustingeach of said flaps, means for delivering equal quantities of: liquid under pressure toeach of said piston motors for effecting a duplication of adjustment of said flaps irrespective of variations in the air resistance to movement encountered by said respective flaps, said means comprising a housing having a single liquid'inlet,means for supplying a single stream of liquid under high pressure to raid single liquid inlet, said housing being further provided with a pair of separate outlets for discharging said liquidi therefrom in two equally divided pressure streams-supplying said-respective ones of said piston motors, said housing being formed with a pair of parallel gear Vunit reg ceiving chambers, each. chamber including in :forv .operationA in 4 i turn a pairl of overlapping cylindrical bores, gears received in said bores meshing in said overiapping areas, meansconnectingsald gears together for operation in unison, said chambers being in common communication on Vthe inlet side ofrsaid' gears with said single inlet and in` independent communication with said separate outlets on the outlet side of said -gears,said high pressure inletii stream being effective to rotate said gear units and means in communication with said divided streams responsive to an increase in resistance to flow in the divided stream leading to one of said piston motors eilective to throttle the flow in said other divided stream leading to said other piston motor to thus increase-the back pressure on the corresponding 4pair of said gears in communication wtih said other stream to the sameA value as. the back pressure on the other pair of said gears in said one'of said streams whereby i' the volumetric efilciencies of said gear units are maintained `equal, and duplicate quantities of liquid are metered to' said respective piston motors for duplicating the arcuate movement ot said tiaps.

3. In an assembly adapted to form part of the control for an aircraft including means dening a pair of remotely-located surface sections having means pivotally supporting the same for`r arcuate adjustment tomodify the cooperation of saidY surface sectionswith the air-stream, liquid pressure-responsive piston motors for arcuately adjusting each of said surface sections, means 4for delivering accurate 'quantities of liquid to eachof said` piston mowrs for effecting duplication'- of adjustment of said surface sections irrespective of variations in the air resistance encountered bysaid respective sections, said means comprising la housing having a single inlet open-` ing for receiving-a single stream of liquid, a pair of separate outlets for discharging said liquid in two divided streams, conduit means connecting said respective outlet streams to said piston motorsfsaid housing being formed with a pair ',i

with said separate outlets on the outlet side of saidgears and means in communicationy with said means comprising aY housing having a slngle'iniet liquidopening for receiving said stream of liquidand a4 plurality of separate outlets ,for discharging said liquid in a pair of divided streams, conduits leading from said outlets to'said respective piston motors, said housing including means forming a plurality of separate gear receiving chambers, pairs of meshing gears received in each chamber,

ysaid chamber-defining means including a partition between each adjacent pair of gears, means connecting-said gears together for rotation in unison, said chambers being in common communication on o ne side with said inlet andr each chamber being in independent communication with a different one of said separate outlets, separate valve means disposed in communicationwith each of said divided streams for controlling the resistance to flow therethrough, and means responsive to a relative rise in pressure in one of said streams leading to one of said piston motors effective to urgesaid valve in communication with said other outletV towards closed position to thus cause a rise in the pressure in said otheroutlet stream whereby to maintain the back pressure on each of said pairs of gears the same and thus cause the volumetric efiiciencies o f each pair of gears to be thel same and sai devices to have duplicate'movement.

5. In a liquid pressure operated system, including a pair of remotely located liquid pressure-responsive piston motor-operated devices subject to differences in the load conditions to which the same are subjected, means providing avhigh pressure liquid supply stream, means for dividing' said high pressure stream into a pair of streamsqof 'equal quantities and delivering the same to' saidrespective piston motors in said equal quantities irrespective ofdifferences in the resistances to operation oil'ered by said respective devices due to said diierences in loading thereon, said means comprising a housing hav-l .ing a single inlet liquid opening for receiving said stream of high pressure liquidl and a plurality: of separate outlets forA discharging said liquid in a pair of divided streams,'conduits leadf ing from said outlets to said respective piston motors,.said housing including means forming a plurality of separate gear receiving chambers.

said inlet'and in independent communication Y divided streams responsive to an'increase in re.- i

` sistance to liquid ow to one of said piston4 motors caused by a difference in air resistance acting on the-:correspondingsurface section effective to throttle the now in said other divided stream to said other motor tothus increase the back pressure on the corresponding gears in said other streamto the same value as the-back pressure I on the corresponding gears in said'one of said divided streams whereby the volumetric eilciencies of said gear units are maintained equal and said surface sections are moved-in synchronism. 4. In a liquid pressure operated system, in-

cluding a pair of remotely located liquid pressureresponsive piston' motor operated devices subject to differences in load conditions, means providing a liquid supply stream, means for divid-` ing said stream into a pair of streams of equal quantities and delivering the same to said respective piston motors in said equal quantities irrespective of differencesin the resistance to operation offered by said respective devices, said pairs of meshing gears received in each chamber, said chamber-definingmeans including a parti- .tion between each adjacent pair of gears, meansA connecting said gears together for rotation in unison, said chambersbeing in, common communication on one side with said inlet and each chamber being in independent communication with a different one ofrsaid separate outlets, said high pressure inlet stream being effective to rotate said gears in said separate chambers, separate valve means disposed in communication with each of said divided streamswfor controlling the resistance to flowV therethrough, and `means responsive to a relative rise in pressure in one of said streams leading toone of said piston motors effective to urge said valve in communication withv the other of said divided streams towards 'closed position to thus cause a rise in the back pressure in said other stream whereby to maintain the back pressure on eachY of said pairs of gears the same and thus cause the volumetric einclencies of each pair of gears, to be the same and saiddevices to have duplicate movement.V

6. The combination with a plurality of remotely located liquid pressure-responsive piston motorfoperated devices .subject to Adifferent Aload conditions, of means for delivering liquid under pressure to each of said piston motors in such relative quantities as to produce identical movement of said devices irrespective of variations in said load conditions, said means comprising a housing having a single liquid inlet opening for receiving a single stream of liquid and a pair of separate liquid outlets for discharging said 'liquid in a pair of divided streams, conduit means delivering each of said divided streams to said respective piston motors, said housing including meansy forming a plurality of separate parallel gear-receiving chambers, pairs of meshing gears received i'n each chamber, said chamber-dening means including a partition between each adjacent pair of gears, means connecting said gears together for rotation in unison, said chambers being in common communication on one side with said inlet and each chamber being in independent communication with a separate one of said outlets, means dening a pair of cylindrical bores, one end of each of said bores being in communication with a separate one of said outlets, the other end of each of said bores being closed, valve seats positioned between the ends of each of said bores, means forming outlet passages from each of said bores intersecting the same at points between said valve seats and the closed ends of said bores. a. separate valve v assembly received in each of said bores and each including a disc-like valve for reception on said respective seats, a piston-like portion extending from each of said valves beyond said position of communication with said corresponding outlet port in the direction of `said closed ends, a flexible seal associated with each one of said piston-like portions and permitting flow yfrom the under side of said piston into said cylindrical bore therebeyond in the direction of said closed ends, but preventing return ow past said piston, means placing said cylindrical bores in communication with one another beyond said piston-like portions, whereby the occurrence of uid pressure at one of said outlets above the value of fluid pressure at the other of said outlets is effective to cause a flow of liquid from said outlet of higher pressure past the corresponding piston and seal and into communication with the piston-like portion and seal of the other Valve assembly, causing the same to urge said other valve towardmits corresponding seat with a pressure equal to the differential pressure between said two outlets whereby to maintain the back pressures on said respective pairs of gears equal with the result that the volumetric efficiencies of said pairs of gears are maintained equal and said devices are operated in synchronism.

JOHN A. LAUCK. 

